Ion removal pH adjustment device

Abstract

The ion removal pH adjustment device comprises a water treatment unit having a first electrode, a second electrode, and an electrically insulating separator arranged to separate the first and second electrodes and through which liquid passes; a power supply unit that applies electricity to the water treatment unit; and a pH adjustment operation control unit that controls the operation of the power supply unit.The pH adjustment operation control unit applies electricity to the first and second electrodes using the power supply unit to perform ion removal and pH adjustment.

Description

[Technical Field]

[0001] The present disclosure relates to an ion removal and pH adjustment device that removes impurities from water. [Background technology]

[0002] Generally, substances such as calcium ions, magnesium ions, or silica in water cause scale deposition in pipes or in areas where water is used, resulting in reduced performance of the pipes or equipment that uses the water. To prevent scale deposition, desalination treatment is sometimes used to remove ions from the water and adjust the pH of the water. Desalination is mainly carried out to prevent scale deposition by removing calcium ions or magnesium ions. Silica is not removed by desalination treatment and becomes easily soluble in water at a pH of 9 or higher, so pH adjustment is carried out separately to prevent scale deposition due to silica. Desalination treatment uses reverse osmosis membranes, ion exchange resins, or flow-through capacitors, etc. pH adjustment is carried out by adding alkaline agents, etc.

[0003] Patent Document 1 discloses a water treatment system including a desalination unit that performs electrostatic desalination treatment, an ion-selective removal unit that selectively removes divalent ions, and a pH adjustment unit that adjusts the pH of water treated in the ion-selective removal unit. In Patent Document 1, the desalination unit and the ion-selective removal unit are used to remove calcium ions or magnesium ions that cause scale deposition from the water, and then a pH adjustment unit adjusts the pH of the water treated in the ion-selective removal unit. In this way, Patent Document 1 aims to dissolve silica in the water and suppress scale deposition caused by silica. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6189422 Summary of the Invention [Problem to be solved by the invention]

[0005] However, a water treatment system such as that described in Patent Document 1, which aims to suppress the deposition of scale, requires multiple water treatment devices, making the entire water treatment system complex.

[0006] The present disclosure has been made to solve the above-mentioned problems, and has an object to provide an ion removal pH adjustment device with a simple configuration. [Means for solving the problem]

[0007] The ion removal pH adjustment device according to the present disclosure includes a water treatment section having a first electrode, a second electrode, and an electrically insulating separator arranged to separate the first electrode and the second electrode, through which a liquid passes; a power supply section that applies electricity to the water treatment section; a pH adjustment operation control section that controls the operation of the power supply section; and a circuit switching section that switches the direction of electricity applied from the power supply section. The pH adjustment operation control section applies electricity to the first electrode and the second electrode using the power supply section to perform ion removal and pH adjustment, and sets at least one of the direction of electricity, current value, voltage application time, and current application time to be applied to the first electrode and the second electrode according to a target pH value, pH range, and pH increase / decrease width in the water treatment section, and controls the power supply section and the circuit switching section based on the set values. The water treatment unit further comprises a first current collector for applying electricity to the first electrode, a second current collector for applying electricity to the second electrode, an inlet provided on the second current collector through which the water to be treated flows, and an outlet provided on the first current collector through which the water to be treated flows, and is configured so that water introduced into the water treatment unit passes through the water treatment unit in the following order: the inlet, the second electrode, the separator, the first electrode, and the outlet. . [Effects of the Invention]

[0008] According to the present disclosure, the pH adjustment operation control unit performs ion removal and pH adjustment. In this way, multiple water treatment devices are not required to achieve both reduction of target ion concentrations in water and pH adjustment. Therefore, the configuration of the ion removal / pH adjustment device is simple. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram showing an ion removal pH adjustment device according to a first embodiment. [Figure 2] FIG. 2 is a schematic diagram showing a water treatment unit according to the first embodiment. [Figure 3] 3 is a flowchart showing the operation of the ion removal pH adjustment device according to the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of an ion removal pH adjustment device according to the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the embodiments described below. The dimensional relationships between components in the following drawings, including FIG. 1, may differ from those in reality. In the following description, directional terms are used as appropriate to facilitate understanding of the present disclosure. However, these terms are for the purpose of explaining the present disclosure and do not limit the present disclosure. Examples of directional terms include "up," "down," "right," "left," "front," and "rear." In the following description, the liquid flowing into the ion removal pH adjustment device will be referred to as "water to be treated," and the liquid flowing out of the ion removal pH adjustment device will be referred to as "treated water." Furthermore, parts that supply the water to be treated to the water treatment unit, such as pumps and supply valves, will be referred to as "water supply units."

[0011] Embodiment 1 FIG. 1 is a schematic diagram showing an ion removal pH adjustment apparatus 200 according to a first embodiment. As shown in FIG. 1, the ion removal pH adjustment apparatus 200 includes a water treatment unit 100, a power supply unit 8, a circuit switching unit 9, a pH adjustment operation control unit 10, a pump 11, and a wastewater destination switching valve 12. Water to be treated is introduced into the water treatment unit 100 by the pump 11. After being treated in the water treatment unit 100, the water is transferred to the wastewater destination switching valve 12. The wastewater destination switching valve 12 switches whether the treated water flowing out of the water treatment unit 100 is transferred to equipment or a place of use that uses the treated water, or to a wastewater destination such as a drain.

[0012] (Water treatment unit 100) FIG. 2 is a schematic diagram showing a water treatment device 100 according to the first embodiment. As shown in FIG. 2, the water treatment device 100 includes a first current collector 1, a first electrode 2, a separator 3, a second electrode 4, a second current collector 5, an inlet 6, and an outlet 7. The water treatment device 100 is configured such that the second current collector 5, the second electrode 4, the separator 3, the first electrode 2, and the first current collector 1 are stacked in this order. The water treatment device 100 includes an inlet 6 through which the water to be treated flows into the second current collector 5, and an outlet 7 through which the treated water flows out of the first current collector 1. Water introduced into the water treatment device 100 according to the present embodiment passes through the inlet 6, the second electrode 4, the separator 3, the first electrode 2, and the outlet 7 in this order. By passing the water through the water treatment device 100 in this manner, the concentration of target ions can be reduced and the pH can be adjusted effectively. In the water treatment unit 100, when electricity is applied from the power supply unit 8, ions contained in the water to be treated are adsorbed onto the electrodes and removed from the water. In addition, the water treatment unit 100 desorbs the ions adsorbed onto the electrodes by short-circuiting the electrodes or applying electricity in the opposite direction to that used for ion adsorption. Note that, hereinafter, the process of adsorbing and removing ions from water is referred to as the ion adsorption process, and the process of desorbing adsorbed ions is referred to as the ion desorption process.

[0013] The first current collector 1 and the second current collector 5 are used to apply electricity to the first electrode 2 and the second electrode 4. They are made of good electrical conductors, such as graphite sheet, graphite plate, Grafoil®, titanium plate, stainless steel plate, and copper plate. When electricity is applied to the first electrode 2 and the second electrode 4, ions contained in the water to be treated are adsorbed onto the electrodes and removed from the water. The first electrode 2 and the second electrode 4 desorb the adsorbed ions by short-circuiting the electrodes or applying electricity between the electrodes in the opposite direction to that used for ion adsorption. Electrodes that have high conductivity and a large specific surface area and therefore a large capacitance as a capacitor are often used, such as powdered activated carbon, granular activated carbon, porous carbon, porous conductive beads, porous metal, activated carbon fiber, activated carbon nonwoven fabric, activated carbon sheet, and carbon aerogel. When granular activated carbon is used as an electrode without being processed into a sheet, an outflow prevention member can be installed between the first electrode 2 and the outlet 7 and between the second electrode 4 and the inlet 6. The outflow prevention member may be installed only between the first electrode 2 and the outlet 7 or between the second electrode 4 and the inlet 6. When granular activated carbon is used, it may be processed into a plate or sheet, but it can also be used as an electrode without processing. The separator 3 separates the first electrode 2 and the second electrode 4 and has the function of preventing contact between the electrodes to prevent short circuits between the electrodes. The separator 3 is made of a material that is electrically insulating and allows liquid to pass through easily, such as filter paper, porous film, nonwoven fabric, or foam material.

[0014] (Power supply part 8) The power supply unit 8 is connected to a pH adjustment operation control unit 10, which controls the application of electricity to the water treatment unit 100. The pH adjustment operation control unit 10 controls the magnitude of the voltage or current applied to the water treatment unit 100. The circuit switching unit 9 is connected to the pH adjustment operation control unit 10.

[0015] (Circuit switching unit 9) The circuit switching unit 9 is provided between the water treatment unit 100 and the power supply unit 8, and controls the direction of the applied electricity so that the treated water has a target pH. The circuit switching unit 9 may have any configuration as long as it can switch the electricity as described above, and may be, for example, a switch circuit.

[0016] (pH adjustment operation control unit 10) The pH adjustment operation control unit 10 is connected to a power supply unit 8, a circuit switching unit 9, a pump 11, and a drainage destination switching valve 12. The pH adjustment operation control unit 10 controls the power supply unit 8, the circuit switching unit 9, the pump 11, and the drainage destination switching valve 12 so that the pH of the treated water reaches the target pH. The pH adjustment operation control unit 10 can be implemented using a programmable logic controller (PLC), sequencer, numerical control device, or other device for operating the device according to specified conditions. Each functional unit realized by the pH adjustment operation control unit 10 may be implemented by individual hardware, or the functional units may be integrated into a single piece of hardware. When the pH adjustment operation control unit 10 is a central processing unit (CPU), each function executed by the pH adjustment operation control unit 10 is implemented by software, firmware, or a combination of software and firmware. The software and firmware are written as programs and stored in memory.

[0017] The CPU realizes each function of the pH adjustment operation control unit 10 by reading and executing programs stored in memory. Here, the memory may be, for example, a non-volatile or volatile semiconductor memory such as RAM, ROM, flash memory, EPROM, or EEPROM. Note that some of the functions of the pH adjustment operation control unit 10 may be realized by dedicated hardware, and other functions may be realized by software or firmware. Furthermore, the pH adjustment operation control unit 10 may be equipped with a storage device that stores past detection results or initially input data. In this case, the power supply unit 8, circuit switching unit 9, pump 11, and wastewater destination switching valve 12 are controlled based on the past detection results or initially input data so that the pH of the treated water reaches the target pH. The pH adjustment operation control unit 10 may also be equipped with a timer capable of measuring time. A time measurement means such as a timer may be provided as a time management unit separate from the pH adjustment operation control unit 10. The time management unit may be included in the pH adjustment operation control unit 10, or if not, may be connected to the pH adjustment operation control unit 10. In this case, the power supply unit 8, the circuit switching unit 9, the pump 11, and the drain destination switching valve 12 are controlled so that the pH of the treated water reaches the target pH based on the set time.

[0018] In this way, the pH adjustment operation control unit 10 sets at least one of the direction of electricity to be applied to the first electrode 2 and the second electrode 4, the voltage value, the current value, the voltage application time, and the current application time, depending on the target pH value, pH range, and pH increase / decrease range in the water treatment unit 100, and controls the power supply unit 8 and the circuit switching unit 9 based on the set values.

[0019] FIG. 3 is a flowchart showing the operation of the ion removal pH adjustment device 200 according to the first embodiment. Next, the operation of the ion removal pH adjustment device 200 will be described. As shown in FIG. 3, first, a target pH of the treated water is set in the pH adjustment operation control unit 10 (step S1). A target value may be set for the pH, or a pH increase or decrease range relative to the pH of the water to be treated may be set. Alternatively, a predetermined pH or less, a predetermined pH or more, or a predetermined pH range such as pH 4 to 7 may be set. When the target pH is set based on the pH of the water to be treated, a treated water pH inspection unit that measures the pH of the water to be treated may be provided. When a treated water pH inspection unit is provided, it is provided between the source of water to be treated and the pump 11, or between the pump 11 and the water treatment unit 100.

[0020] Next, the pH adjustment operation control unit 10 sets the conditions for applying electricity to the water treatment unit 100 so that the pH becomes the set target pH (step S2). The conditions for applying electricity include the direction of voltage or current application, the value of the applied voltage or current, and the application time of the voltage or current.

[0021] Then, the ion adsorption process of the water treatment unit 100 is started (step S3). The ion adsorption process is started in the pH adjustment operation control unit 10 under the operating conditions set in step S2. The pH adjustment operation control unit 10 controls the power supply unit 8 and the circuit switching unit 9 to apply electricity to the water treatment unit 100 under predetermined electrical application conditions. The pH adjustment operation control unit 10 also controls the pump 11 to introduce the water to be treated into the water treatment unit 100. Furthermore, the pH adjustment operation control unit 10 controls the discharge destination switching valve 12 so that the treated water flows from the water treatment unit 100 to the equipment that uses the treated water.

[0022] When a predetermined time has elapsed since the control of the pH adjustment operation control unit 10 was started (step S4), the ion adsorption process ends (step S5). Thereafter, the ion desorption process starts (step S6). After the ion desorption process ends (step S7), the process returns to step S1 again. Note that if the target pH does not change for each ion adsorption process, the process may return to step S3 after step S7.

[0023] According to the first embodiment, the pH adjustment operation control unit 10 performs ion removal and pH adjustment. Thus, to achieve both reduction of the target ion concentration in water and pH adjustment, multiple water treatment devices are not required. Therefore, the configuration of the ion removal pH adjustment device 200 is simple.

[0024] In the first embodiment, the electrical application conditions are set in step S2 to achieve the target pH, but the flow rate of the water to be treated introduced into the water treatment unit 100 may also be set. That is, the pH adjustment operation control unit 10 sets the flow rate of the water to be supplied to the water treatment unit 100 according to the target pH value, pH range, and pH increase / decrease range in the water treatment unit 100, and controls the water supply unit based on the set value. When the flow rate is set, a water to be treated flow rate measuring unit may be provided to measure the flow rate of the water to be treated introduced into the water treatment unit 100.

[0025] Furthermore, during the ion adsorption process, the electrical application conditions or the flow rate conditions do not have to be constant and may be changed. In step S3, the case where the pH adjustment operation control unit 10 controls the pump 11 is exemplified. However, if the supply source of the water to be treated is a source with water pressure, such as a water tap, an on-off valve such as a solenoid valve may be provided instead of the pump 11, and the opening and closing of the on-off valve may be controlled by the pH adjustment operation control unit 10.

[0026] In step S4, the timing for ending the ion adsorption process is illustrated as being determined by the pH adjustment operation control unit 10 when a predetermined period of time for the ion adsorption process has elapsed. However, the ion removal pH adjustment device 200 may be provided with a treated water pH inspection unit that measures the pH of the treated water, and the end of the ion adsorption process may be determined based on the pH measurement results from the treated water pH inspection unit. The treated water pH inspection unit may be provided between the water treatment unit 100 and the wastewater destination switching valve 12, or between the wastewater destination switching valve 12 and an apparatus or location that uses the treated water. Furthermore, a treated water quality inspection unit that measures the quality of the water introduced into the water treatment unit 100 may be provided before the treated water is introduced into the water treatment unit 100. When a water quality testing unit for treated water is provided, the water quality testing unit measures the water quality of the water to be treated. Based on the results, the pH adjustment operation control unit 10 sets at least one of the direction of electricity to be applied to the first electrode 2 and the second electrode 4, the voltage value, the current value, the voltage application time, and the current application time according to the target pH value, pH range, and pH increase / decrease range for the water treatment unit 100, and controls the power supply unit 8 and the circuit switching unit 9 based on the set values. The water quality testing unit for treated water can measure items such as electrical conductivity, pH, total dissolved solids, ion concentration, and organic matter concentration. It may measure multiple water quality indicators or a single water quality indicator. The water treatment unit 100 removes ions from the water and adjusts the water's pH. It is not particularly limited as long as it is a capacitive deionization (CDI) device. [Explanation of symbols]

[0027] 1 first current collector, 2 first electrode, 3 separator, 4 second electrode, 5 second current collector, 6 inlet, 7 outlet, 8 power supply unit, 9 circuit switching unit, 10 pH adjustment operation control unit, 11 pump, 12 wastewater destination switching valve, 100 water treatment unit, 200 ion removal pH adjustment device.

Claims

1. A water treatment unit having a first electrode, a second electrode, and a separator that is arranged to space the first electrode and the second electrode apart, has electrical insulation properties, and through which liquid passes; A power supply unit that applies electricity to the water treatment unit, The system includes a pH adjustment operation control unit that controls the operation of the power supply unit, The pH adjustment operation control unit is The power supply unit applies electricity to the first and second electrodes to perform ion removal and pH adjustment. Ion removal pH adjustment device.

2. The circuit further comprises a circuit switching unit that switches the direction of the electricity applied from the power supply unit. The ion removal pH adjustment device according to claim 1.

3. The pH adjustment operation control unit is In the water treatment unit, at least one of the following is set according to the target pH value, pH range, and pH increase / decrease range: the direction of electricity applied to the first electrode and the second electrode, the voltage value, the current value, the voltage application time, and the current application time. Based on the set value, the power supply unit and the circuit switching unit are controlled. The ion removal pH adjustment device according to claim 2.

4. The water treatment unit is further provided with a water supply unit that supplies water to be treated, The pH adjustment operation control unit is The flow rate of water supplied to the water treatment unit is set according to the target pH value, pH range, and pH increase / decrease range in the water treatment unit, and the water supply unit is controlled based on the set value. An ion removal pH adjustment device according to any one of claims 1 to 3.

5. In the water treatment section, water flows in the order of the first electrode, the separator, and the second electrode. An ion removal pH adjustment device according to any one of claims 1 to 3.

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